"""Base module for runners"""
import os
import signal
from gettext import gettext as _

from lutris import runtime, settings
from lutris.api import get_default_runner_version
from lutris.command import MonitoredCommand
from lutris.config import LutrisConfig
from lutris.database.games import get_game_by_field
from lutris.exceptions import GameConfigError, UnavailableLibrariesError
from lutris.runners import RunnerInstallationError
from lutris.util import flatpak, strings, system
from lutris.util.extract import ExtractFailure, extract_archive
from lutris.util.linux import LINUX_SYSTEM
from lutris.util.log import logger


class Runner:  # pylint: disable=too-many-public-methods

    """Generic runner (base class for other runners)."""

    multiple_versions = False
    platforms = []
    runnable_alone = False
    game_options = []
    runner_options = []
    system_options_override = []
    context_menu_entries = []
    require_libs = []
    runner_executable = None
    entry_point_option = "main_file"
    download_url = None
    arch = None  # If the runner is only available for an architecture that isn't x86_64
    flatpak_id = None

    def __init__(self, config=None):
        """Initialize runner."""
        if config:
            self.has_explicit_config = True
            self._config = config
            self.game_data = get_game_by_field(config.game_config_id, "configpath")
        else:
            self.has_explicit_config = False
            self._config = None
            self.game_data = {}

    def __lt__(self, other):
        return self.name < other.name

    @property
    def description(self):
        """Return the class' docstring as the description."""
        return self.__doc__

    @description.setter
    def description(self, value):
        """Leave the ability to override the docstring."""
        self.__doc__ = value  # What the shit

    @property
    def name(self):
        return self.__class__.__name__

    @property
    def directory(self):
        return os.path.join(settings.RUNNER_DIR, self.name)

    @property
    def config(self):
        if not self._config:
            self._config = LutrisConfig(runner_slug=self.name)
        return self._config

    @config.setter
    def config(self, new_config):
        self._config = new_config
        self.has_explicit_config = new_config is not None

    @property
    def game_config(self):
        """Return the cascaded game config as a dict."""
        if not self.has_explicit_config:
            logger.warning("Accessing game config while runner wasn't given one.")

        return self.config.game_config

    @property
    def runner_config(self):
        """Return the cascaded runner config as a dict."""
        return self.config.runner_config

    @property
    def system_config(self):
        """Return the cascaded system config as a dict."""
        return self.config.system_config

    @property
    def default_path(self):
        """Return the default path where games are installed."""
        return self.system_config.get("game_path")

    @property
    def game_path(self):
        """Return the directory where the game is installed."""
        game_path = self.game_data.get("directory")
        if game_path:
            return game_path

        if self.has_explicit_config:
            # Default to the directory where the entry point is located.
            entry_point = self.game_config.get(self.entry_point_option)
            if entry_point:
                return os.path.dirname(os.path.expanduser(entry_point))
        return ""

    def resolve_game_path(self):
        """Returns the path where the game is found; if game_path does not
        provide a path, this may try to resolve the path by runner-specific means,
        which can find things like /usr/games when applicable."""
        return self.game_path

    @property
    def library_folders(self):
        """Return a list of paths where a game might be installed"""
        return []

    @property
    def working_dir(self):
        """Return the working directory to use when running the game."""
        return self.game_path or os.path.expanduser("~/")

    @property
    def shader_cache_dir(self):
        """Return the cache directory for this runner to use. We create
        this if it does not exist."""
        path = os.path.join(settings.SHADER_CACHE_DIR, self.name)
        if not os.path.isdir(path):
            os.mkdir(path)
        return path

    @property
    def nvidia_shader_cache_path(self):
        """The path to place in __GL_SHADER_DISK_CACHE_PATH; NVidia
        will place its cache cache in a subdirectory here."""
        return self.shader_cache_dir

    @property
    def discord_client_id(self):
        if self.game_data.get("discord_client_id"):
            return self.game_data.get("discord_client_id")

    def get_platform(self):
        return self.platforms[0]

    def get_runner_options(self):
        runner_options = self.runner_options[:]
        if self.runner_executable:
            runner_options.append(
                {
                    "option": "runner_executable",
                    "type": "file",
                    "label": _("Custom executable for the runner"),
                    "advanced": True,
                }
            )
        return runner_options

    def get_executable(self):
        if "runner_executable" in self.runner_config:
            runner_executable = self.runner_config["runner_executable"]
            if os.path.isfile(runner_executable):
                return runner_executable
        if not self.runner_executable:
            raise ValueError("runner_executable not set for {}".format(self.name))
        return os.path.join(settings.RUNNER_DIR, self.runner_executable)

    def get_command(self):
        exe = self.get_executable()
        if system.path_exists(exe):
            return [exe]
        if flatpak.is_app_installed(self.flatpak_id):
            return flatpak.get_run_command(self.flatpak_id)
        return []

    def get_env(self, os_env=False, disable_runtime=False):
        """Return environment variables used for a game."""
        env = {}
        if os_env:
            env.update(os.environ.copy())

        # By default we'll set NVidia's shader disk cache to be
        # per-game, so it overflows less readily.
        env["__GL_SHADER_DISK_CACHE"] = "1"
        env["__GL_SHADER_DISK_CACHE_PATH"] = self.nvidia_shader_cache_path

        # Override SDL2 controller configuration
        sdl_gamecontrollerconfig = self.system_config.get("sdl_gamecontrollerconfig")
        if sdl_gamecontrollerconfig:
            path = os.path.expanduser(sdl_gamecontrollerconfig)
            if system.path_exists(path):
                with open(path, "r", encoding='utf-8') as controllerdb_file:
                    sdl_gamecontrollerconfig = controllerdb_file.read()
            env["SDL_GAMECONTROLLERCONFIG"] = sdl_gamecontrollerconfig

        # Set monitor to use for SDL 1 games
        sdl_video_fullscreen = self.system_config.get("sdl_video_fullscreen")
        if sdl_video_fullscreen and sdl_video_fullscreen != "off":
            env["SDL_VIDEO_FULLSCREEN_DISPLAY"] = sdl_video_fullscreen

        # DRI Prime
        if self.system_config.get("dri_prime"):
            env["DRI_PRIME"] = "1"

        # Prime vars
        prime = self.system_config.get("prime")
        if prime:
            env["__NV_PRIME_RENDER_OFFLOAD"] = "1"
            env["__GLX_VENDOR_LIBRARY_NAME"] = "nvidia"
            env["__VK_LAYER_NV_optimus"] = "NVIDIA_only"

        # Set PulseAudio latency to 60ms
        if self.system_config.get("pulse_latency"):
            env["PULSE_LATENCY_MSEC"] = "60"

        # Vulkan ICD files
        vk_icd = self.system_config.get("vk_icd")
        if vk_icd:
            env["VK_ICD_FILENAMES"] = vk_icd

        runtime_ld_library_path = None

        if not disable_runtime and self.use_runtime():
            runtime_env = self.get_runtime_env()
            runtime_ld_library_path = runtime_env.get("LD_LIBRARY_PATH")

        if runtime_ld_library_path:
            ld_library_path = env.get("LD_LIBRARY_PATH")
            env["LD_LIBRARY_PATH"] = os.pathsep.join(filter(None, [
                runtime_ld_library_path, ld_library_path]))

        # Apply user overrides at the end
        env.update(self.system_config.get("env") or {})

        return env

    def get_runtime_env(self):
        """Return runtime environment variables.

        This method may be overridden in runner classes.
        (Notably for Lutris wine builds)

        Returns:
            dict

        """
        return runtime.get_env(prefer_system_libs=self.system_config.get("prefer_system_libs", True))

    def apply_launch_config(self, gameplay_info, launch_config):
        """Updates the gameplay_info to reflect a launch_config section. Called only
        if a non-default config is chosen."""
        gameplay_info["command"] = self.get_launch_config_command(gameplay_info, launch_config)

        config_working_dir = self.get_launch_config_working_dir(launch_config)

        if config_working_dir:
            gameplay_info["working_dir"] = config_working_dir

    def get_launch_config_command(self, gameplay_info, launch_config):
        """Generates a new command for the gameplay_info, to implement the launch_config.
        Returns a new list of strings; the caller can modify it further.

        If launch_config has no command, this builds one from the gameplay_info command
        and the 'exe' value in the launch_config.

        Runners override this when required to control the command used."""

        if "command" in launch_config:
            command = strings.split_arguments(launch_config["command"])
        elif "command" in gameplay_info:
            command = [gameplay_info["command"][0]]
        else:
            logger.debug("No command in %s", gameplay_info)
            logger.debug(launch_config)
            # The 'file' sort of gameplay_info cannot be made to use a configuration
            raise GameConfigError(_("The runner could not find a command to apply the configuration to."))

        exe = self.get_launch_config_exe(launch_config)
        if exe:
            command.append(exe)

        if launch_config.get("args"):
            command += strings.split_arguments(launch_config["args"])

        return command

    def get_launch_config_exe(self, launch_config):
        """Locates the "exe" of the launch config. If it appears
        to be relative to the game's working_dir, this will try to
        adjust it to be relative to the config's instead.
        """
        exe = launch_config.get("exe")
        config_working_dir = self.get_launch_config_working_dir(launch_config)

        if exe and config_working_dir and not os.path.isabs(exe):
            exe_from_config = self.resolve_config_path(exe, config_working_dir)
            exe_from_game = self.resolve_config_path(exe)

            if os.path.exists(exe_from_game) and not os.path.exists(exe_from_config):
                relative = os.path.relpath(exe_from_game, start=config_working_dir)
                if not relative.startswith("../"):
                    return relative

        return exe

    def get_launch_config_working_dir(self, launch_config):
        """Extracts the "working_dir" from the config, and resolves this relative
        to the game's working directory, so that an absolute path results.

        This returns None if no working_dir is present, or if it found to be missing.
        """
        config_working_dir = launch_config.get("working_dir")
        if config_working_dir:
            config_working_dir = self.resolve_config_path(config_working_dir)
            if os.path.isdir(config_working_dir):
                return config_working_dir

        return None

    def resolve_config_path(self, path, relative_to=None):
        """Interpret a path taken from the launch_config relative to
        a working directory, using the game's working_dir if that is omitted.

        This is provided as a method so the WINE runner can try to convert
        Windows-style paths to usable paths.
        """
        if not os.path.isabs(path):
            if not relative_to:
                relative_to = self.working_dir

            if relative_to:
                return os.path.join(relative_to, path)

        return path

    def prelaunch(self):
        """Run actions before running the game, override this method in runners; raise an
        exception if prelaunch fails, and it will be reported to the user, and
        then the game won't start."""
        available_libs = set()
        for lib in set(self.require_libs):
            if lib in LINUX_SYSTEM.shared_libraries:
                if self.arch:
                    if self.arch in [_lib.arch for _lib in LINUX_SYSTEM.shared_libraries[lib]]:
                        available_libs.add(lib)
                else:
                    available_libs.add(lib)
        unavailable_libs = set(self.require_libs) - available_libs
        if unavailable_libs:
            raise UnavailableLibrariesError(unavailable_libs, self.arch)

    def get_run_data(self):
        """Return dict with command (exe & args list) and env vars (dict).

        Reimplement in derived runner if need be."""
        return {"command": self.get_command(), "env": self.get_env()}

    def run(self, ui_delegate):
        """Run the runner alone."""
        if not self.runnable_alone:
            return
        if not self.is_installed():
            if not self.install_dialog(ui_delegate):
                logger.info("Runner install cancelled")
                return

        command_data = self.get_run_data()
        command = command_data.get("command")
        env = (command_data.get("env") or {}).copy()

        self.prelaunch()

        command_runner = MonitoredCommand(command, runner=self, env=env)
        command_runner.start()

    def use_runtime(self):
        if runtime.RUNTIME_DISABLED:
            logger.info("Runtime disabled by environment")
            return False
        if self.system_config.get("disable_runtime"):
            logger.info("Runtime disabled by system configuration")
            return False
        return True

    def install_dialog(self, ui_delegate):
        """Ask the user if they want to install the runner.

        Return success of runner installation.
        """

        if ui_delegate.show_install_yesno_inquiry(
            question=_("The required runner is not installed.\n"
                       "Do you wish to install it now?"),
            title=_("Required runner unavailable"),
        ):
            if hasattr(self, "get_version"):
                version = self.get_version(use_default=False)  # pylint: disable=no-member
                self.install(ui_delegate, version=version)
            else:
                self.install(ui_delegate)

            return self.is_installed()
        return False

    def is_installed(self):
        """Return whether the runner is installed"""
        if system.path_exists(self.get_executable()):
            return True
        return self.flatpak_id and flatpak.is_app_installed(self.flatpak_id)

    def get_runner_version(self, version=None, lutris_only=False):
        """Get the appropriate version for a runner, as with get_default_runner_version(),
        but this method allows the runner to apply its configuration."""
        return get_default_runner_version(self.name, version)

    def install(self, install_ui_delegate, version=None, callback=None):
        """Install runner using package management systems."""
        logger.debug(
            "Installing %s (version=%s, callback=%s)",
            self.name,
            version,
            callback,
        )
        opts = {"install_ui_delegate": install_ui_delegate, "callback": callback}
        if self.download_url:
            opts["dest"] = self.directory
            return self.download_and_extract(self.download_url, **opts)
        runner = self.get_runner_version(version, lutris_only=True)
        if not runner:
            raise RunnerInstallationError(_("Failed to retrieve {} ({}) information").format(self.name, version))

        if "wine" in self.name:
            opts["merge_single"] = True
            opts["dest"] = os.path.join(
                self.directory, "{}-{}".format(runner["version"], runner["architecture"])
            )

        if self.name == "libretro" and version:
            opts["merge_single"] = False
            opts["dest"] = os.path.join(settings.RUNNER_DIR, "retroarch/cores")
        self.download_and_extract(runner["url"], **opts)

    def download_and_extract(self, url, dest=None, **opts):
        install_ui_delegate = opts["install_ui_delegate"]
        merge_single = opts.get("merge_single", False)
        callback = opts.get("callback")
        tarball_filename = os.path.basename(url)
        runner_archive = os.path.join(settings.CACHE_DIR, tarball_filename)
        if not dest:
            dest = settings.RUNNER_DIR

        install_ui_delegate.download_install_file(url, runner_archive)
        self.extract(archive=runner_archive, dest=dest, merge_single=merge_single, callback=callback)

    def extract(self, archive=None, dest=None, merge_single=None, callback=None):
        if not system.path_exists(archive):
            raise RunnerInstallationError(_("Failed to extract {}").format(archive))
        try:
            extract_archive(archive, dest, merge_single=merge_single)
        except ExtractFailure as ex:
            logger.error("Failed to extract the archive %s file may be corrupt", archive)
            raise RunnerInstallationError(_("Failed to extract {}: {}").format(archive, ex)) from ex
        os.remove(archive)

        if self.name == "wine":
            logger.debug("Clearing wine version cache")
            from lutris.util.wine.wine import get_wine_versions
            get_wine_versions.cache_clear()

        if self.runner_executable:
            runner_executable = os.path.join(settings.RUNNER_DIR, self.runner_executable)
            if os.path.isfile(runner_executable):
                system.make_executable(runner_executable)

        if callback:
            callback()

    def remove_game_data(self, app_id=None, game_path=None):
        system.remove_folder(game_path)

    def can_uninstall(self):
        return os.path.isdir(self.directory)

    def uninstall(self):
        runner_path = self.directory
        if os.path.isdir(runner_path):
            system.remove_folder(runner_path)

    def find_option(self, options_group, option_name):
        """Retrieve an option dict if it exists in the group"""
        if options_group not in ['game_options', 'runner_options']:
            return None
        output = None
        for item in getattr(self, options_group):
            if item["option"] == option_name:
                output = item
                break
        return output

    def force_stop_game(self, game):
        """Stop the running game. If this leaves any game processes running,
        the caller will SIGKILL them (after a delay)."""
        game.kill_processes(signal.SIGTERM)

    def extract_icon(self, game_slug):
        """The config UI calls this to extract the game icon. Most runners do not
        support this and do nothing. This is not called if a custom icon is installed
        for the game."""
